The efficacy of intradetrusor onabotulinumtoxinA injections for management of idiopathic overactive bladder has been well established. The injections are typically performed in the office setting utilizing local analgesia, most commonly a 20-30 minute intravesical instillation of lidocaine. There is limited data evaluating alternative bladder analgesics.
To compare pain scores in women undergoing intradetrusor onabotulinumtoxinA for idiopathic overactive bladder (OAB) between women randomized to pre-procedure oral phenazopyridine versus intravesical lidocaine.
Non-pregnant adult females with idiopathic overactive bladder, scheduled for office injection of 100 units intradetrusor onabotulinumtoxinA were randomized to either 200mg of oral phenazopyridine taken 1-2 hours preprocedure versus a 20-minute preprocedure intravesical instillation of 50mL 2% lidocaine. We excluded participants with neurogenic bladder, and those who had received intradetrusor onabotulinumtoxinA injections in the previous 12 months. The primary outcome was pain measured by a 100mm visual analog scale (VAS). Demographic characteristics and overall satisfaction with the procedure were also collected. Providers answered questions about cystoscopic visualization, ease of procedure, and perception of participant comfort. Prespecified non-inferiority margin was set to equal the anticipated MCID of 14mm. A planned sample of 100 participants, 50 in each treatment arm, provided 80% power to detect non-inferiority at a significance level of .05. We performed a modified intention to treat analysis and compared variables by T-test or Fisher's exact test.
111 participants were enrolled; complete data was obtained for 100 participants. 47 participants were randomized to phenazopyridine and 53 to lidocaine. Baseline characteristics did not differ between groups. 19.6% and 20.8% in the phenazopyridine and lidocaine groups, respectively, had previously undergone intradetrusor onabotulinumtoxinA injections. The mean post-procedure pain was 2.7mm lower in the phenazopyridine group vs the lidocaine group (95%CI: -11.3 to. 10.7) demonstrating non-inferiority. Greater than 90% of participants in both groups stated the pain was tolerable. Slightly more participants reported being "very satisfied" in the lidocaine group, although this was not statistically different (50.0% vs 40.4%, p = 0.34). Providers reported clear visualization in 89.4% of participants in the phenazopyridine group versus 100% in the lidocaine group (p=0.02). Provider perception of participant comfort and overall ease of procedure was not different between groups. Length of time in the exam room was significantly shorter in the phenazopyridine versus the lidocaine group (44.4 vs 57.5 minutes, p=0.0003).
In women receiving intradetrusor onabotulinumtoxinA injections for idiopathic OAB, oral phenazopyridine was non-inferior to intravesical lidocaine for procedural pain control. Phenazopyridine is well-tolerated by participants, allows for the procedure to be performed with similar ease, and is associated with shorter appointment times.
American journal of obstetrics and gynecology. 2022 May 14 [Epub ahead of print]
Lauren E Stewart, Moiuri Siddique, Kristin M Jacobs, Christina A Raker, Vivian W Sung
Providence, RI; Division of Urogynecology and Reconstructive Pelvic Surgery, Warren Alpert Medical School of Brown University/Women & Infants Hospital of Rhode Island; 101 Plain Street, 5th Floor, Providence, RI 02903., Chicago, IL; Division of Female Pelvic Medicine and Reconstructive Surgery, Rush University Medical Center; 1725 W. Harrison St. Suite 1129 Chicago, IL 60612., Providence, RI; Department of Obstetrics and Gynecology, Division of Research, Warren Alpert Medical School of Brown University/Women & Infants Hospital of Rhode Island; 101 Plain Street, 5th Floor, Providence, RI 02903.